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Arhar A, Pavlič A, Hočevar L. Characteristics of oral health of patients with X-linked hypophosphatemia: case reports and literature review. BDJ Open 2024; 10:42. [PMID: 38821917 PMCID: PMC11143263 DOI: 10.1038/s41405-024-00223-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/22/2024] [Accepted: 04/25/2024] [Indexed: 06/02/2024] Open
Abstract
BACKGROUND Oral health is impaired in X-linked hypophosphatemia (XLH), resulting in delayed dental development, malocclusion, and radiographic abnormalities. This study investigates the oral manifestations in Slovenian XLH patients, focusing on enamel and dentin abnormalities and a literature review of spontaneous periapical abscesses in XLH cases. OBJECTIVES To report XLH patients with specific oral signs and symptoms, histological analysis of affected teeth, and review of reported cases of XLH patients with spontaneous periapical abscesses. METHODS Case reports: Seven XLH patients from the National Registry of Patients with Rare Diseases underwent a detailed oral examination, including X-ray reviews. The patients who were expected to have tooth exfoliation or extraction were asked to donate their teeth for histological analysis by scanning electron microscopy. LITERATURE SEARCH A literature search of four electronic databases and a manual bibliography search aimed to identify documented cases of XLH with periapical abscesses up to January 21, 2024. Inclusion criteria were confirmed XLH patients with periapical abscesses in English peer-reviewed publications. RESULTS Tooth samples from three XLH patients showed reduced dentin mineralisation, affecting one-third to one-half of the outer dentin. Inadequate mineralisation, uneven dentin tubules, and cracks and chipping in the enamel were observed, indicating mineralisation deviations. Similar cracks extended into the dentin and were also present in the root of the examined tooth. Based on the content of the 75 items identified in the search, spontaneous abscesses are not uncommon in patients with XLH. CONCLUSIONS XLH significantly affects patients' lives and requires lifelong treatment. Dental examinations consistently revealed oral problems, including malocclusion. Histological analysis confirmed structural changes, especially in the dentin. Despite continued treatment, XLH patients may have an increased risk of oral pathologies. Further research is needed to understand the impact of XLH and its treatment on dental health.
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Affiliation(s)
- Ana Arhar
- Department of Paediatric and Preventive Dentistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, Ljubljana, Slovenia
| | - Alenka Pavlič
- Department of Paediatric and Preventive Dentistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, Ljubljana, Slovenia
- Department of Paediatric and Preventive Dentistry, University Medical Centre Ljubljana, Zaloška 2, Ljubljana, Slovenia
| | - Luka Hočevar
- Department of Paediatric and Preventive Dentistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, Ljubljana, Slovenia.
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Carpenter KA, Alkhatib DO, Dulion BA, Guirado E, Patel S, Chen Y, George A, Ross RD. Sclerostin antibody improves alveolar bone quality in the Hyp mouse model of X-linked hypophosphatemia (XLH). Int J Oral Sci 2023; 15:47. [PMID: 37813865 PMCID: PMC10562382 DOI: 10.1038/s41368-023-00252-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 10/11/2023] Open
Abstract
X-linked hypophosphatemia (XLH) is a rare disease of elevated fibroblast growth factor 23 (FGF23) production that leads to hypophosphatemia and impaired mineralization of bone and teeth. The clinical manifestations of XLH include a high prevalence of dental abscesses and periodontal disease, likely driven by poorly formed structures of the dentoalveolar complex, including the alveolar bone, cementum, dentin, and periodontal ligament. Our previous studies have demonstrated that sclerostin antibody (Scl-Ab) treatment improves phosphate homeostasis, and increases long bone mass, strength, and mineralization in the Hyp mouse model of XLH. In the current study, we investigated whether Scl-Ab impacts the dentoalveolar structures of Hyp mice. Male and female wild-type and Hyp littermates were injected with 25 mg·kg-1 of vehicle or Scl-Ab twice weekly beginning at 12 weeks of age and euthanized at 20 weeks of age. Scl-Ab increased alveolar bone mass in both male and female mice and alveolar tissue mineral density in the male mice. The positive effects of Scl-Ab were consistent with an increase in the fraction of active (nonphosphorylated) β-catenin, dentin matrix protein 1 (DMP1) and osteopontin stained alveolar osteocytes. Scl-Ab had no effect on the mass and mineralization of dentin, enamel, acellular or cellular cementum. There was a nonsignificant trend toward increased periodontal ligament (PDL) attachment fraction within the Hyp mice. Additional PDL fiber structural parameters were not affected by Scl-Ab. The current study demonstrates that Scl-Ab can improve alveolar bone in adult Hyp mice.
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Affiliation(s)
- Kelsey A Carpenter
- Department of Anatomy & Cell Biology, Rush University Medical Center, Chicago, IL, USA
| | - Delia O Alkhatib
- Department of Anatomy & Cell Biology, Rush University Medical Center, Chicago, IL, USA
| | - Bryan A Dulion
- Department of Anatomy & Cell Biology, Rush University Medical Center, Chicago, IL, USA
| | - Elizabeth Guirado
- Department of Oral Biology, The University of Illinois at Chicago, Chicago, IL, USA
| | - Shreya Patel
- Department of Anatomy & Cell Biology, Rush University Medical Center, Chicago, IL, USA
| | - Yinghua Chen
- Department of Oral Biology, The University of Illinois at Chicago, Chicago, IL, USA
| | - Anne George
- Department of Oral Biology, The University of Illinois at Chicago, Chicago, IL, USA
| | - Ryan D Ross
- Department of Anatomy & Cell Biology, Rush University Medical Center, Chicago, IL, USA.
- Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, USA.
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA.
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Ross R, Carpenter K, Alkhatib D, Dulion B, Guirado E, Patel S, Chen Y, George A. Sclerostin antibody improves alveolar bone quality in the Hyp mouse model of X-Linked Hypophosphatemia (XLH). RESEARCH SQUARE 2023:rs.3.rs-2762671. [PMID: 37090634 PMCID: PMC10120757 DOI: 10.21203/rs.3.rs-2762671/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
X-linked hypophosphatemia (XLH) is a rare disease of elevated fibroblast growth factor 23 (FGF23) production that leads to hypophosphatemia and poor mineralization of bone and teeth. The clinical manifestations of XLH include a high prevalence of dental abscesses, likely driven by poorly formed structures of the dentoalveolar complex, including the alveolar bone, cementum, dentin, and periodontal ligament. Our previous studies have demonstrated that sclerostin antibody (Scl-Ab) treatment improves phosphate homeostasis, and increases bone mass, strength and mineralization in the Hyp mouse model of XLH. In the current study, we investigated whether Scl-Ab impacts the dentoalveolar structures of Hyp mice. Male and female wild-type and Hyp littermates were injected with 25 mg/kg of vehicle or Scl-Ab twice weekly beginning at 12 weeks of age and euthanized at 20 weeks of age. Scl-Ab increased alveolar bone mass in both male and female mice and alveolar tissue mineral density in the male mice. The positive effects of Scl-Ab were consistent with an increase in the fraction of active (non-phosphorylated) β-catenin stained alveolar osteocytes. Scl-Ab had no effect on mineralized tissues of the tooth - dentin, enamel, acellular and cellular cementum. There was a non-significant trend toward increased periodontal ligament (PDL) attachment fraction within the Hyp mice. Additional PDL fibral structural parameters were not affected by Scl-Ab. The current study demonstrates that Scl-Ab can improve alveolar bone in the Hyp mouse model of XLH.
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Affiliation(s)
| | | | | | | | | | | | - Yinghua Chen
- University of Illinois Chicago College of Dentistry
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Millington G, Joseph J, Xiao L, Vijaykumar A, Mina M, Hurley MM. Fibroblast Growth Factor 2 High Molecular Weight Isoforms in Dentoalveolar Mineralization. Calcif Tissue Int 2022; 110:93-103. [PMID: 34245331 PMCID: PMC8738103 DOI: 10.1007/s00223-021-00888-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 07/02/2021] [Indexed: 01/03/2023]
Abstract
Transgenic mice overexpressing human high molecular weight fibroblast growth factor 2 (HMWFGF2) isoforms in osteoblast and odontoblast lineages (HMWTg) exhibit decreased dentin and alveolar bone mineralization, enlarged pulp chamber, and increased fibroblast growth factor 23 (FGF23). We examined if the alveolar bone and dentin mineralization defects in HMWTg mice resulted from increased FGF23 expression and whether an FGF23 neutralizing antibody could rescue the hypomineralization phenotype. HMWTg and VectorTg control mice were given subcutaneous injections of FGF23 neutralizing antibody twice/week starting at postnatal day 21 for 6 weeks. Since Calcitriol (1,25D) have direct effects in promoting bone mineralization, we also determined if 1,25D protects against the defective dentin and alveolar bone mineralization. Therefore, HMWTg mice were given subcutaneous injections of 1,25D daily or concomitantly with FGF23 neutralizing antibody for 6 weeks. Our results showed that HMWTg mice displayed thickened predentin, alveolar bone hypomineralization, and enlarged pulp chambers. FGF23 neutralizing antibody and 1,25D monotherapy partially rescued the dentin mineralization defects and the enlarged pulp chamber phenotype in HMWTg mice. 1,25D alone was not sufficient to rescue the alveolar bone hypomineralization. Interestingly, HMWTg mice treated with both FGF23 neutralizing antibody and 1.25D further rescued the enlarged pulp chamber size, and dentin and alveolar bone mineralization defects. We conclude that the dentin and alveolar bone mineralization defects in HMWTg mice might result from increased FGF23 expression. Our results show a novel role of HMWFGF2 on dentoalveolar mineralization.
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Affiliation(s)
- Grethel Millington
- University of Connecticut School of Dental Medicine, Farmington, CT, USA.
| | - Johnny Joseph
- NYU Langone Health, Postdoctoral Pediatric Dentistry Program, Brooklyn, NY, 11220, USA
| | - Liping Xiao
- Department of Medicine, University of Connecticut School of Medicine, UConn Health, Farmington, CT, 06030-052, USA
| | - Anushree Vijaykumar
- Department of Craniofacial Sciences, University of Connecticut School of Dental Medicine, Farmington, CT, USA
| | - Mina Mina
- Department of Craniofacial Sciences, University of Connecticut School of Dental Medicine, Farmington, CT, USA
| | - Marja M Hurley
- Department of Medicine, University of Connecticut School of Medicine, UConn Health, Farmington, CT, 06030-052, USA.
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Baroncelli GI, Zampollo E, Manca M, Toschi B, Bertelloni S, Michelucci A, Isola A, Bulleri A, Peroni D, Giuca MR. Pulp chamber features, prevalence of abscesses, disease severity, and PHEX mutation in X-linked hypophosphatemic rickets. J Bone Miner Metab 2021; 39:212-223. [PMID: 32772199 DOI: 10.1007/s00774-020-01136-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 07/27/2020] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Rickets, growth failure, and recurrent periapical abscesses with fistulae are main signs in patients with X-linked hypophosphatemic rickets (XLH). Prevalence of abscesses, pulp chamber features, biochemical findings, disease severity, and PHEX gene mutation were examined. MATERIALS AND METHODS Pulp chambers size, shape, and morphology were assessed by orthopantomography in XLH patients (n = 24, age 5.8 ± 1.6 years) and in sex and age-matched healthy controls (n = 23, age 6.2 ± 1.4 years). XLH patients received conventional treatment (3.5 ± 1.9 years). Pulp chamber features were assessed in teeth of primary dentition and in the permanent left mandibular first molar and compared with those of controls. Rickets severity score was assessed at wrist, knee, and ankle. RESULTS The mean pulp chamber area/tooth area ratio, mean pulp chamber height/pulp chamber width ratio, and prominence of pulp horns into the tooth crown in primary and secondary molars were significantly higher in patients than in controls and in patients suffered abscesses than in patients without abscesses. Sixteen patients (67%) had a history of abscesses; incisors were affected more than canines and molars. Severity of rickets and mean serum parathyroid hormone (PTH) levels were significantly higher, and mean serum 1,25-dihydroxyvitamin D [1,25(OH)2D] levels significantly lower in patients suffered abscesses than in patients without abscesses. PHEX gene mutations were not correlated with dental phenotype and disease severity. CONCLUSION Enlarged pulp chambers with altered shape and morphology affected the majority of XLH patients predisposing to recurrent periapical abscesses with fistulae. Dental phenotype was associated with severity of rickets, high serum PTH, and low serum 1,25(OH)2D levels.
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Affiliation(s)
- Giampiero I Baroncelli
- Division of Pediatrics, Endocrine Unit, Department of Obstetrics, Gynecology and Pediatrics, University-Hospital, Via Roma 67, 56126, Pisa, Italy.
| | - Elisa Zampollo
- Division of Dentistry and Oral Surgery, Department of Surgical Specialties, University-Hospital, Pisa, Italy
| | - Mario Manca
- Unit of Orthopedics, Usl Northwest-Tuscany, Versilia Hospital, Camaiore, Italy
| | - Benedetta Toschi
- Division of Medical Genetics, Department of Medical and Oncological Area, University-Hospital, Pisa, Italy
| | - Silvano Bertelloni
- Division of Pediatrics, Endocrine Unit, Department of Obstetrics, Gynecology and Pediatrics, University-Hospital, Via Roma 67, 56126, Pisa, Italy
| | - Angela Michelucci
- Unit of Molecular Genetics, Department of Laboratory Medicine, University-Hospital, Pisa, Italy
| | - Alessandro Isola
- Unit of Orthopedics, Usl Northwest-Tuscany, Versilia Hospital, Camaiore, Italy
| | - Alessandra Bulleri
- Unit of Radiodiagnostic, Department of Diagnostic Imaging, University-Hospital, Pisa, Italy
| | - Diego Peroni
- Division of Pediatrics, Endocrine Unit, Department of Obstetrics, Gynecology and Pediatrics, University-Hospital, Via Roma 67, 56126, Pisa, Italy
| | - Maria Rita Giuca
- Division of Dentistry and Oral Surgery, Department of Surgical Specialties, University-Hospital, Pisa, Italy
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Baroncelli GI, Mora S. X-Linked Hypophosphatemic Rickets: Multisystemic Disorder in Children Requiring Multidisciplinary Management. Front Endocrinol (Lausanne) 2021; 12:688309. [PMID: 34421819 PMCID: PMC8378329 DOI: 10.3389/fendo.2021.688309] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/14/2021] [Indexed: 12/14/2022] Open
Abstract
X-linked hypophosphatemic rickets (XLH) is the commonest inherited form of rickets. It is caused by an impaired regulation of fibroblast growth factor 23 (FGF23) due to a PHEX gene mutation, which leads to reduced tubular reabsorption of phosphate and renal 1α-hydroxylase activity and increased renal 24-hydroxylase activity. Hypophosphatemia associated with renal phosphate wasting, normal serum levels of calcium, parathyroid hormone, and 25-hydroxyvitamin D represents the main biochemical sign in affected patients. Patients with XLH show rickets and osteomalacia, severe deformities of the lower limbs, bone and muscular pain, stunted growth, and reduced quality of life. However, XLH is a multisystemic disorder requiring multidisciplinary approaches in specialized subdisciplines. Severe complications may occur in patients with XLH including craniosynostosis, hearing loss, progressive bone deformities, dental and periodontal recurrent lesions, and psychosocial distress. Moreover, long-term conventional treatment with active vitamin D metabolites and oral inorganic phosphate salts may cause endocrinological complications such as secondary or tertiary hyperparathyroidism, and adverse events in kidney as hypercalciuria, nephrocalcinosis, and nephrolithiasis. However, conventional treatment does not improve phosphate metabolism and it shows poor and slow effects in improving rickets lesions and linear growth. Recently, some trials of treatment with recombinant human IgG1 monoclonal antibody that targets FGF23 (burosumab) showed significant improvement of serum phosphate concentration and renal tubular reabsorption of phosphate that were associated with a rapid healing of radiologic signs of rickets, reduced muscular and osteoarticular pain, and improved physical function, being more effective for the treatment of patients with XLH in comparison with conventional therapy. Therefore, a global management of patients with XLH is strongly recommended and patients should be seen regularly by a multidisciplinary team of experts.
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Affiliation(s)
- Giampiero Igli Baroncelli
- Pediatric and Adolescent Endocrinology, Department of Obstetrics, Gynecology and Pediatrics, University Hospital, Pisa, Italy
- *Correspondence: Giampiero Igli Baroncelli, ; Stefano Mora,
| | - Stefano Mora
- Laboratory of Pediatric Endocrinology and Bone Densitometry Service, IRCCS San Raffaele Scientific Institute, Milan, Italy
- *Correspondence: Giampiero Igli Baroncelli, ; Stefano Mora,
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7
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Zhang H, Chavez MB, Kolli TN, Tan MH, Fong H, Chu EY, Li Y, Ren X, Watanabe K, Kim DG, Foster BL. Dentoalveolar Defects in the Hyp Mouse Model of X-linked Hypophosphatemia. J Dent Res 2020; 99:419-428. [PMID: 31977267 DOI: 10.1177/0022034520901719] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Mutations in PHEX cause X-linked hypophosphatemia (XLH), a form of hypophosphatemic rickets. Hyp (Phex mutant) mice recapitulate the XLH phenotype. Dental disorders are prevalent in individuals with XLH; however, underlying dentoalveolar defects remain incompletely understood. We analyzed Hyp mouse dentoalveolar defects at 42 and 90 d postnatal to comparatively define effects of XLH on dental formation and function. Phex mRNA was expressed by odontoblasts (dentin), osteocytes (bone), and cementocytes (cellular cementum) in wild-type (WT) mice. Enamel density was unaffected, though enamel volume was significantly reduced in Hyp mice. Dentin defects in Hyp molars were indicated histologically by wide predentin, thin dentin, and extensive interglobular dentin, confirming micro-computed tomography (micro-CT) findings of reduced dentin volume and density. Acellular cementum was thin and showed periodontal ligament detachment. Mechanical testing indicated dramatically altered periodontal mechanical properties in Hyp versus WT mice. Hyp mandibles demonstrated expanded alveolar bone with accumulation of osteoid, and micro-CT confirmed decreased bone volume fraction and alveolar bone density. Cellular cementum area was significantly increased in Hyp versus WT molars owing to accumulation of hypomineralized cementoid. Histology, scanning electron microscopy, and nanoindentation revealed hypomineralized "halos" surrounding Hyp cementocyte and osteocyte lacunae. Three-dimensional micro-CT analyses confirmed larger cementocyte/osteocyte lacunae and significantly reduced perilacunar mineral density. While long bone and alveolar bone osteocytes in Hyp mice overexpressed fibroblast growth factor 23 (Fgf23), its expression in molars was much lower, with cementocyte Fgf23 expression particularly low. Expression and distribution of other selected markers were disturbed in Hyp versus WT long bone, alveolar bone, and cementum, including osteocyte/cementocyte marker dentin matrix protein 1 (Dmp1). This study reports for the first time a quantitative analysis of the Hyp mouse dentoalveolar phenotype, including all mineralized tissues. Novel insights into cellular cementum provide evidence for a role for cementocytes in perilacunar mineralization and cementum biology.
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Affiliation(s)
- H Zhang
- Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA, USA
| | - M B Chavez
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - T N Kolli
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - M H Tan
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - H Fong
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - E Y Chu
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Y Li
- Department of Oral Maxillofacial Surgery, West China School of Stomatology, Sichuan University, Chengdu, China
| | - X Ren
- Department of Periodontics, School of Stomatology, Shanxi Medical University, Taiyuan, China
| | - K Watanabe
- Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - D G Kim
- Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - B L Foster
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
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Abstract
Fibroblast growth factor 23 (FGF23), one of the endocrine fibroblast growth factors, is a principal regulator in the maintenance of serum phosphorus concentration. Binding to its cofactor αKlotho and a fibroblast growth factor receptor is essential for its activity. Its regulation and interaction with other factors in the bone-parathyroid-kidney axis is complex. FGF23 reduces serum phosphorus concentration through decreased reabsorption of phosphorus in the kidney and by decreasing 1,25 dihydroxyvitamin D (1,25(OH)2D) concentrations. Various FGF23-mediated disorders of renal phosphate wasting share similar clinical and biochemical features. The most common of these is X-linked hypophosphatemia (XLH). Additional disorders of FGF23 excess include autosomal dominant hypophosphatemic rickets, autosomal recessive hypophosphatemic rickets, fibrous dysplasia, and tumor-induced osteomalacia. Treatment is challenging, requiring careful monitoring and titration of dosages to optimize effectiveness and to balance side effects. Conventional therapy for XLH and other disorders of FGF23-mediated hypophosphatemia involves multiple daily doses of oral phosphate salts and active vitamin D analogs, such as calcitriol or alfacalcidol. Additional treatments may be used to help address side effects of conventional therapy such as thiazides to address hypercalciuria or nephrocalcinosis, and calcimimetics to manage hyperparathyroidism. The recent development and approval of an anti-FGF23 antibody, burosumab, for use in XLH provides a novel treatment option.
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Affiliation(s)
- Anisha Gohil
- Indiana University School of Medicine, Riley Hospital for Children, Fellow, Endocrinology and Diabetes, 705 Riley Hospital Drive, Room 5960, Indianapolis, IN 46202, USA, E-mail:
| | - Erik A Imel
- Indiana University School of Medicine, Riley Hospital for Children, Associate Professor of Medicine and Pediatrics, 1120 West Michigan Street, CL 459, Indianapolis, IN 46202, USA
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Imel EA, Biggin A, Schindeler A, Munns CF. FGF23, Hypophosphatemia, and Emerging Treatments. JBMR Plus 2019; 3:e10190. [PMID: 31485552 PMCID: PMC6715782 DOI: 10.1002/jbm4.10190] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 02/13/2019] [Accepted: 02/26/2019] [Indexed: 01/03/2023] Open
Abstract
FGF23 is an important hormonal regulator of phosphate homeostasis. Together with its co-receptor Klotho, it modulates phosphate reabsorption and both 1α-hydroxylation and 24-hydroxylation in the renal proximal tubules. The most common FGF23-mediated hypophosphatemia is X-linked hypophosphatemia (XLH), caused by mutations in the PHEX gene. FGF23-mediated forms of hypophosphatemia are characterized by phosphaturia and low or low-normal calcitriol concentrations, and unlike nutritional rickets, these cannot be cured with nutritional vitamin D supplementation. Autosomal dominant and autosomal recessive forms of FGF23-mediated hypophosphatemias show a similar pathophysiology, despite a variety of different underlying genetic causes. An excess of FGF23 activity has also been associated with a number of other conditions causing hypophosphatemia, including tumor-induced osteomalacia, fibrous dysplasia of the bone, and cutaneous skeletal hypophosphatemia syndrome. Historically phosphate supplementation and therapy using analogs of highly active vitamin D (eg, calcitriol, alfacalcidol, paricalcitol, eldecalcitol) have been used to manage conditions involving hypophosphatemia; however, recently a neutralizing antibody for FGF23 (burosumab) has emerged as a promising treatment agent for FGF23-mediated disorders. This review discusses the progression of clinical trials for burosumab for the treatment of XLH and its recent availability for clinical use. Burosumab may have potential for treating other conditions associated with FGF23 overactivity, but these are not yet supported by trial data. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Erik A Imel
- Division of EndocrinologyIndiana University School of Medicine, Indianapolis, INUSA
| | - Andrew Biggin
- The University of Sydney Children's Hospital Westmead Clinical School, University of SydneySydneyAustralia
- Department of EndocrinologyThe Children's Hospital at WestmeadWestmeadAustralia
| | - Aaron Schindeler
- The University of Sydney Children's Hospital Westmead Clinical School, University of SydneySydneyAustralia
- Orthopaedic Research Unit, The Children's Hospital at WestmeadWestmeadAustralia
| | - Craig F Munns
- The University of Sydney Children's Hospital Westmead Clinical School, University of SydneySydneyAustralia
- Department of EndocrinologyThe Children's Hospital at WestmeadWestmeadAustralia
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Jing J, Feng J, Li J, Han X, He J, Ho TV, Du J, Zhou X, Urata M, Chai Y. Antagonistic interaction between Ezh2 and Arid1a coordinates root patterning and development via Cdkn2a in mouse molars. eLife 2019; 8:46426. [PMID: 31259687 PMCID: PMC6602580 DOI: 10.7554/elife.46426] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 06/05/2019] [Indexed: 02/05/2023] Open
Abstract
Patterning is a critical step during organogenesis and is closely associated with the physiological function of organs. Tooth root shapes are finely tuned to provide precise occlusal support to facilitate the function of each tooth type. However, the mechanism regulating tooth root patterning and development is largely unknown. In this study, we provide the first in vivo evidence demonstrating that Ezh2 in the dental mesenchyme determines patterning and furcation formation during dental root development in mouse molars. Mechanistically, an antagonistic interaction between epigenetic regulators Ezh2 and Arid1a controls Cdkn2a expression in the dental mesenchyme to regulate dental root patterning and development. These findings indicate the importance of balanced epigenetic regulation in determining the tooth root pattern and the integration of roots with the jaw bones to achieve physiological function. Collectively, our study provides important clues about the regulation of organogenesis and has general implications for tooth regeneration in the future.
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Affiliation(s)
- Junjun Jing
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, United States.,State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jifan Feng
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, United States
| | - Jingyuan Li
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, United States
| | - Xia Han
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, United States
| | - Jinzhi He
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, United States.,State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Thach-Vu Ho
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, United States
| | - Jiahui Du
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, United States
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Mark Urata
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, United States
| | - Yang Chai
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, United States
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Beck-Nielsen SS, Mughal Z, Haffner D, Nilsson O, Levtchenko E, Ariceta G, de Lucas Collantes C, Schnabel D, Jandhyala R, Mäkitie O. FGF23 and its role in X-linked hypophosphatemia-related morbidity. Orphanet J Rare Dis 2019; 14:58. [PMID: 30808384 PMCID: PMC6390548 DOI: 10.1186/s13023-019-1014-8] [Citation(s) in RCA: 145] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/30/2019] [Indexed: 12/29/2022] Open
Abstract
Background X-linked hypophosphatemia (XLH) is an inherited disease of phosphate metabolism in which inactivating mutations of the Phosphate Regulating Endopeptidase Homolog, X-Linked (PHEX) gene lead to local and systemic effects including impaired growth, rickets, osteomalacia, bone abnormalities, bone pain, spontaneous dental abscesses, hearing difficulties, enthesopathy, osteoarthritis, and muscular dysfunction. Patients with XLH present with elevated levels of fibroblast growth factor 23 (FGF23), which is thought to mediate many of the aforementioned manifestations of the disease. Elevated FGF23 has also been observed in many other diseases of hypophosphatemia, and a range of animal models have been developed to study these diseases, yet the role of FGF23 in the pathophysiology of XLH is incompletely understood. Methods The role of FGF23 in the pathophysiology of XLH is here reviewed by describing what is known about phenotypes associated with various PHEX mutations, animal models of XLH, and non-nutritional diseases of hypophosphatemia, and by presenting molecular pathways that have been proposed to contribute to manifestations of XLH. Results The pathophysiology of XLH is complex, involving a range of molecular pathways that variously contribute to different manifestations of the disease. Hypophosphatemia due to elevated FGF23 is the most obvious contributor, however localised fluctuations in tissue non-specific alkaline phosphatase (TNAP), pyrophosphate, calcitriol and direct effects of FGF23 have been observed to be associated with certain manifestations. Conclusions By describing what is known about these pathways, this review highlights key areas for future research that would contribute to the understanding and clinical treatment of non-nutritional diseases of hypophosphatemia, particularly XLH.
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Affiliation(s)
| | - Zulf Mughal
- Royal Manchester Children's Hospital, Manchester, UK
| | | | - Ola Nilsson
- Karolinska Institutet, Stockholm, Sweden and Örebro University, Örebro, Sweden
| | | | - Gema Ariceta
- Hospital Universitario Materno-Infantil Vall d'Hebron, Universitat Autonoma de Barcelona, Barcelona, Spain
| | | | - Dirk Schnabel
- University Children's Hospital of Berlin, Berlin, Germany
| | | | - Outi Mäkitie
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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12
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Coyac BR, Falgayrac G, Penel G, Schmitt A, Schinke T, Linglart A, McKee MD, Chaussain C, Bardet C. Impaired mineral quality in dentin in X-linked hypophosphatemia. Connect Tissue Res 2018; 59:91-96. [PMID: 29745817 DOI: 10.1080/03008207.2017.1417989] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
X-linked hypophosphatemia (XLH) is a skeletal disorder arising from mutations in the PHEX gene, transmitted in most cases as an X-linked dominant trait. PHEX deficiency leads to renal phosphate wasting and hypophosphatemia, as well as impaired mineralization of bone and dentin, resulting in severe skeletal and dental complications. Dentin mineralization defects appear as characteristic, large interglobular spaces resulting from the lack of fusion of calculospherites in the circumpulpal region during the mineralization process. Here, we examined changes in the composition and structure of dentin using Raman spectroscopy on XLH human teeth, and using transmission electron microscopy on the dentin of Hyp mice (the murine model of XLH). The dentin of patients with XLH showed changes in the quality of the apatitic mineral, with greater carbonate substitution and lower crystallinity compared to the dentin of age-matched control teeth. In addition, ultrastructural analysis by transmission electron microscopy revealed a major disorganization of the peri- and intertubular structure of the dentin, with odontoblast processes residing within an unmineralized matrix sheath in the Hyp mouse. Taken together, these results indicate that like for bone and tooth cementum, there are impaired mineral quality and matrix changes in XLH dentin reflecting high sensitivity to systemic serum phosphate levels and possibly other local changes in the dentin matrix.
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Affiliation(s)
- Benjamin R Coyac
- a Orofacial Pathologies, Imaging and Biotherapies Laboratory EA2496, Dental School , Paris Descartes University , Paris , France.,b Department of Periodontology, U.F.R. of Odontology , Rothschild Hospital, AP-HP, Paris Diderot University , Paris , France
| | - Guillaume Falgayrac
- c EA 4490-PMOI-Physiopathologie des Maladies Osseuses Inflammatoires , Univ. Lille, Univ. Littoral Côte d'Opale , Lille , France
| | - Guillaume Penel
- c EA 4490-PMOI-Physiopathologie des Maladies Osseuses Inflammatoires , Univ. Lille, Univ. Littoral Côte d'Opale , Lille , France
| | - Alain Schmitt
- d Cochin Institute, Transmission Electron Microscopy Platform, INSERM U1016, CNRS UMR8104 , Paris Descartes University Sorbonne Paris Cité , Paris , France
| | - Thorsten Schinke
- e Department of Osteology and Biomechanics , University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Agnès Linglart
- f APHP, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism , Plateforme d'Expertise Paris Sud Maladies Rares and Filière OSCAR , Le Kremlin Bicêtre , France.,g INSERM U1169 , University Paris Sud Paris-Saclay , Le Kremelin Bicêtre, France
| | - Marc D McKee
- h Faculties of Dentistry and Medicine, Department of Anatomy and Cell Biology , McGill University , Montreal , Canada
| | - Catherine Chaussain
- a Orofacial Pathologies, Imaging and Biotherapies Laboratory EA2496, Dental School , Paris Descartes University , Paris , France.,i Department of Odontology , Bretonneau Hospital PNVS, AP-HP , Paris , France
| | - Claire Bardet
- a Orofacial Pathologies, Imaging and Biotherapies Laboratory EA2496, Dental School , Paris Descartes University , Paris , France
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13
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Imel EA, White KE. Pharmacological management of X-linked hypophosphataemia. Br J Clin Pharmacol 2018; 85:1188-1198. [PMID: 30207609 DOI: 10.1111/bcp.13763] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/05/2018] [Accepted: 09/05/2018] [Indexed: 12/25/2022] Open
Abstract
The most common heritable disorder of renal phosphate wasting, X-linked hypophosphataemia (XLH), was discovered to be caused by inactivating mutations in the phosphate regulating gene with homology to endopeptidases on the X-chromosome (PHEX) gene in 1995. Although the exact molecular mechanisms by which PHEX mutations cause disturbed phosphate handling in XLH remain unknown, focus for novel therapies has more recently been based upon the finding that the bone-produced phosphaturic hormone fibroblast growth factor-23 is elevated in XLH patient plasma. Previous treatment strategies for XLH were based upon phosphate repletion plus active vitamin D analogues, which are difficult to manage, fail to address the primary pathogenesis of the disease, and can have deleterious side effects. A novel therapy for XLH directly targeting fibroblast growth factor-23 via a humanized monoclonal antibody (burosumab-twza/CRYSVITA, henceforth referred to just as burosumab) has emerged as an effective, and recently approved, pharmacological treatment for both children and adults. This review will provide an overview of the clinical manifestations of XLH, the molecular pathophysiology, and summarize its current treatment.
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Affiliation(s)
- Erik A Imel
- Department of Medicine, Division of Endocrinology and Metabolism, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Pediatrics, Section of Endocrinology and Diabetology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kenneth E White
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
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14
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Foster BL, Ao M, Salmon CR, Chavez MB, Kolli TN, Tran AB, Chu EY, Kantovitz KR, Yadav M, Narisawa S, Millán JL, Nociti FH, Somerman MJ. Osteopontin regulates dentin and alveolar bone development and mineralization. Bone 2018; 107:196-207. [PMID: 29313816 PMCID: PMC5803363 DOI: 10.1016/j.bone.2017.12.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 11/09/2017] [Accepted: 12/03/2017] [Indexed: 01/09/2023]
Abstract
The periodontal complex is essential for tooth attachment and function and includes the mineralized tissues, cementum and alveolar bone, separated by the unmineralized periodontal ligament (PDL). To gain insights into factors regulating cementum-PDL and bone-PDL borders and protecting against ectopic calcification within the PDL, we employed a proteomic approach to analyze PDL tissue from progressive ankylosis knock-out (Ank-/-) mice, featuring reduced PPi, rapid cementogenesis, and excessive acellular cementum. Using this approach, we identified the matrix protein osteopontin (Spp1/OPN) as an elevated factor of interest in Ank-/- mouse molar PDL. We studied the role of OPN in dental and periodontal development and function. During tooth development in wild-type (WT) mice, Spp1 mRNA was transiently expressed by cementoblasts and strongly by alveolar bone osteoblasts. Developmental analysis from 14 to 240days postnatal (dpn) indicated normal histological structures in Spp1-/- comparable to WT control mice. Microcomputed tomography (micro-CT) analysis at 30 and 90dpn revealed significantly increased volumes and tissue mineral densities of Spp1-/- mouse dentin and alveolar bone, while pulp and PDL volumes were decreased and tissue densities were increased. However, acellular cementum growth was unaltered in Spp1-/- mice. Quantitative PCR of periodontal-derived mRNA failed to identify potential local compensators influencing cementum in Spp1-/- vs. WT mice at 26dpn. We genetically deleted Spp1 on the Ank-/- mouse background to determine whether increased Spp1/OPN was regulating periodontal tissues when the PDL space is challenged by hypercementosis in Ank-/- mice. Ank-/-; Spp1-/- double deficient mice did not exhibit greater hypercementosis than that in Ank-/- mice. Based on these data, we conclude that OPN has a non-redundant role regulating formation and mineralization of dentin and bone, influences tissue properties of PDL and pulp, but does not control acellular cementum apposition. These findings may inform therapies targeted at controlling soft tissue calcification.
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Affiliation(s)
- B L Foster
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA.
| | - M Ao
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - C R Salmon
- Department of Prosthodontics and Periodontics, Division of Periodontics, Piracicaba Dental School, University of Campinas, São Paulo, Brazil
| | - M B Chavez
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - T N Kolli
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - A B Tran
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - E Y Chu
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - K R Kantovitz
- Department of Dental Materials, São Leopoldo Mandic Research Center, Campinas, São Paulo, Brazil
| | - M Yadav
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Research Institute, La Jolla, CA, USA
| | - S Narisawa
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Research Institute, La Jolla, CA, USA
| | - J L Millán
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Research Institute, La Jolla, CA, USA
| | - F H Nociti
- Department of Prosthodontics and Periodontics, Division of Periodontics, Piracicaba Dental School, University of Campinas, São Paulo, Brazil
| | - M J Somerman
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
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15
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Ao M, Chavez MB, Chu EY, Hemstreet KC, Yin Y, Yadav MC, Millán JL, Fisher LW, Goldberg HA, Somerman MJ, Foster BL. Overlapping functions of bone sialoprotein and pyrophosphate regulators in directing cementogenesis. Bone 2017; 105:134-147. [PMID: 28866368 PMCID: PMC5730356 DOI: 10.1016/j.bone.2017.08.027] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 08/24/2017] [Accepted: 08/28/2017] [Indexed: 12/19/2022]
Abstract
Although acellular cementum is essential for tooth attachment, factors directing its development and regeneration remain poorly understood. Inorganic pyrophosphate (PPi), a mineralization inhibitor, is a key regulator of cementum formation: tissue-nonspecific alkaline phosphatase (Alpl/TNAP) null mice (increased PPi) feature deficient cementum, while progressive ankylosis protein (Ank/ANK) null mice (decreased PPi) feature increased cementum. Bone sialoprotein (Bsp/BSP) and osteopontin (Spp1/OPN) are multifunctional extracellular matrix components of cementum proposed to have direct and indirect effects on cell activities and mineralization. Studies on dentoalveolar development of Bsp knockout (Bsp-/-) mice revealed severely reduced acellular cementum, however underlying mechanisms remain unclear. The similarity in defective cementum phenotypes between Bsp-/- mice and Alpl-/- mice (the latter featuring elevated PPi and OPN), prompted us to examine whether BSP is operating by modulating PPi-associated genes. Genetic ablation of Bsp caused a 2-fold increase in circulating PPi, altered mRNA expression of Alpl, Spp1, and Ank, and increased OPN protein in the periodontia. Generation of a Bsp knock-out (KO) cementoblast cell line revealed significantly decreased mineralization capacity, 50% increased PPi in culture media, and increased Spp1 and Ank mRNA expression. While addition of 2μg/ml recombinant BSP altered Spp1, Ank, and Enpp1 expression in cementoblasts, changes resulting from this dose were not dependent on the integrin-binding RGD motif or MAPK/ERK signaling pathway. Decreasing PPi by genetic ablation of Ank on the Bsp-/- mouse background reestablished cementum formation, allowing >3-fold increased acellular cementum volume compared to wild-type (WT). However, deleting Ank did not fully compensate for the absence of BSP. Bsp-/-; Ank-/- double-deficient mice exhibited mean 20-27% reduced cementum thickness and volume compared to Ank-/- mice. From these data, we conclude that the perturbations in PPi metabolism are not solely driving the cementum pathology in Bsp-/- mice, and that PPi is more potent than BSP as a cementum regulator, as shown by the ability to override loss of BSP by lowering PPi. We propose that BSP and PPi work in concert to direct mineralization in cementum and likely other mineralized tissues.
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Affiliation(s)
- M Ao
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - M B Chavez
- Biosciences Division, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - E Y Chu
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - K C Hemstreet
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Y Yin
- National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - M C Yadav
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - J L Millán
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - L W Fisher
- National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - H A Goldberg
- Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - M J Somerman
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - B L Foster
- Biosciences Division, College of Dentistry, The Ohio State University, Columbus, OH, USA.
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16
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Coyac BR, Falgayrac G, Baroukh B, Slimani L, Sadoine J, Penel G, Biosse-Duplan M, Schinke T, Linglart A, McKee MD, Chaussain C, Bardet C. Tissue-specific mineralization defects in the periodontium of the Hyp mouse model of X-linked hypophosphatemia. Bone 2017; 103:334-346. [PMID: 28764922 DOI: 10.1016/j.bone.2017.07.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 07/22/2017] [Accepted: 07/27/2017] [Indexed: 01/28/2023]
Abstract
X-linked hypophosphatemia (XLH) is a dento-osseous disorder caused by inactivating mutations in the PHEX gene, leading to renal phosphate wasting and hypophosphatemia, and impaired mineralization of bones and teeth. In the oral cavity, recent reports suggest a higher susceptibility of XLH patients to periodontitis, where patients present with impaired tooth cementum - a bone-like tissue involved in tooth attachment to the jaw bones and post-eruption tooth positioning - and a higher frequency of intrabony defects. In the present study, the pathobiology of alveolar bone and tooth cementum was investigated in the Hyp mouse, the murine analog of XLH. PHEX deficiency in XLH/Hyp dramatically alters the periodontal phenotype, with hypoplasia of tooth root cementum associated with a lack of periodontal ligament attachment and the presence of an immature apatitic mineral phase of all periodontal mineralized tissues. Challenging the Hyp periodontium in two surgical experimental models - ligature-induced periodontal breakdown and repair, and a model of tooth movement adaptation inducing cementum formation - we show that bone and cementum formation, and their healing, are altered. Bone and cementum mineralization appear similarly disturbed, where hypomineralized pericellular matrix surrounds cells, and where the protein osteopontin (OPN, a mineralization inhibitor) accumulates in a tissue-specific manner, most notably in the perilacunar matrix surrounding osteocytes. Although the pathobiology is different between XLH/Hyp bone and cementum, our results show a major XLH phenotype in oral mineralized tissues consistent with variations in patient susceptibility to periodontal disorders.
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Affiliation(s)
- Benjamin R Coyac
- EA2496, Faculty of Dentistry, Paris Descartes University, Montrouge, France; Department of Periodontology, U.F.R. of Odontology, Rothschild Hospital, AP-HP, Paris Diderot University, Paris, France
| | - Guillaume Falgayrac
- Univ. Lille, Univ. Littoral Côte d'Opale, EA 4490 - PMOI - Physiopathologie des Maladies Osseuses Inflammatoires, F-59000 Lille, France
| | - Brigitte Baroukh
- EA2496, Faculty of Dentistry, Paris Descartes University, Montrouge, France
| | - Lotfi Slimani
- EA2496, Faculty of Dentistry, Paris Descartes University, Montrouge, France
| | - Jérémy Sadoine
- EA2496, Faculty of Dentistry, Paris Descartes University, Montrouge, France
| | - Guillaume Penel
- Univ. Lille, Univ. Littoral Côte d'Opale, EA 4490 - PMOI - Physiopathologie des Maladies Osseuses Inflammatoires, F-59000 Lille, France
| | - Martin Biosse-Duplan
- Department of Odontology, Bretonneau Hospital PNVS, AP-HP, Paris, France; APHP, Reference Center for Rare Disorders of the Calcium and Phosphate Metabolism, Filière OSCAR and Plateforme d'Expertise Maladies Rares Paris-Sud, Hôpital Bicêtre Paris Sud, Le Kremlin Bicêtre, France
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Agnès Linglart
- APHP, Reference Center for Rare Disorders of the Calcium and Phosphate Metabolism, Filière OSCAR and Plateforme d'Expertise Maladies Rares Paris-Sud, Hôpital Bicêtre Paris Sud, Le Kremlin Bicêtre, France; INSERM U1169, Hôpital Bicêtre, Le Kremlin Bicêtre, and Université Paris-Saclay, France
| | - Marc D McKee
- Faculties of Dentistry and Medicine, Department of Anatomy and Cell Biology, McGill University, Montreal, Canada
| | - Catherine Chaussain
- EA2496, Faculty of Dentistry, Paris Descartes University, Montrouge, France; Department of Odontology, Bretonneau Hospital PNVS, AP-HP, Paris, France; APHP, Reference Center for Rare Disorders of the Calcium and Phosphate Metabolism, Filière OSCAR and Plateforme d'Expertise Maladies Rares Paris-Sud, Hôpital Bicêtre Paris Sud, Le Kremlin Bicêtre, France
| | - Claire Bardet
- EA2496, Faculty of Dentistry, Paris Descartes University, Montrouge, France.
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17
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Abstract
The tooth root is an integral, functionally important part of our dentition. The formation of a functional root depends on epithelial-mesenchymal interactions and integration of the root with the jaw bone, blood supply and nerve innervations. The root development process therefore offers an attractive model for investigating organogenesis. Understanding how roots develop and how they can be bioengineered is also of great interest in the field of regenerative medicine. Here, we discuss recent advances in understanding the cellular and molecular mechanisms underlying tooth root formation. We review the function of cellular structure and components such as Hertwig's epithelial root sheath, cranial neural crest cells and stem cells residing in developing and adult teeth. We also highlight how complex signaling networks together with multiple transcription factors mediate tissue-tissue interactions that guide root development. Finally, we discuss the possible role of stem cells in establishing the crown-to-root transition, and provide an overview of root malformations and diseases in humans.
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Affiliation(s)
- Jingyuan Li
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, CA 90033, USA.,Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050, People's Republic of China
| | - Carolina Parada
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, CA 90033, USA
| | - Yang Chai
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, Los Angeles, CA 90033, USA
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18
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Dai J, Si J, Ouyang N, Zhang J, Wu D, Wang X, Shen G. Dental and periodontal phenotypes of Dlx2 overexpression in mice. Mol Med Rep 2017; 15:2443-2450. [PMID: 28447749 PMCID: PMC5428916 DOI: 10.3892/mmr.2017.6315] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 12/12/2016] [Indexed: 11/29/2022] Open
Abstract
Distal-less homeobox 2 (Dlx2) is a member of the homeodomain family of transcription factors and is important for the development of cranial neural crest cells (CNCCs)-derived craniofacial tissues. Previous studies revealed that Dlx2 was expressed in the cementum and a targeted null mutation disrupted tooth development in mice. However, whether Dlx2 overexpression may impair in vivo tooth morphogenesis remains to be elucidated. The present study used a transgenic mouse model to specifically overexpress Dlx2 in neural crest cells in order to identify the dental phenotypes in mice by observation, micro-computed tomography and histological examination. The Dlx2-overexpressed mice exhibited tooth abnormalities including incisor cross-bite, shortened tooth roots, increased cementum deposition, periodontal ligament disorganization and osteoporotic alveolar bone. Therefore, Dlx2 overexpression may alter the alveolar bone, cementum and periodontal ligament (PDL) phenotypes in mice.
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Affiliation(s)
- Jiewen Dai
- Department of Oral and Cranio‑maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Jiawen Si
- Department of Oral and Cranio‑maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Ningjuan Ouyang
- Department of Oral and Cranio‑maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Jianfei Zhang
- Department of Oral and Cranio‑maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Dandan Wu
- Department of Oral and Cranio‑maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Xudong Wang
- Department of Oral and Cranio‑maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
| | - Guofang Shen
- Department of Oral and Cranio‑maxillofacial Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China
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19
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Biosse Duplan M, Coyac BR, Bardet C, Zadikian C, Rothenbuhler A, Kamenicky P, Briot K, Linglart A, Chaussain C. Phosphate and Vitamin D Prevent Periodontitis in X-Linked Hypophosphatemia. J Dent Res 2016; 96:388-395. [PMID: 27821544 DOI: 10.1177/0022034516677528] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
X-linked hypophosphatemia (XLH) is a rare genetic skeletal disease where increased phosphate wasting in the kidney leads to hypophosphatemia and prevents normal mineralization of bone and dentin. Here, we examined the periodontal status of 34 adults with XLH and separated them according to the treatment they received for hypophosphatemia. We observed that periodontitis frequency and severity were increased in adults with XLH and that the severity varied according to the hypophosphatemia treatment. Patients who benefited from an early and continuous vitamin D and phosphate supplementation during their childhood presented less periodontal attachment loss than patients with late or incomplete supplementation. Continued hypophosphatemia treatment during adulthood further improved the periodontal health. Extracted teeth from patients with late or incomplete supplementation showed a strong acellular cementum hypoplasia when compared with age-matched healthy controls. These results show that XLH disturbs not only bone and dentin formation but also cementum and that the constitutional defect of the attachment apparatus is associated with attachment loss.
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Affiliation(s)
- M Biosse Duplan
- 1 Service d'Odontologie, Hôpital Bretonneau, HUPNVS, AP-HP, Paris, France.,2 Faculté de Chirurgie Dentaire, Université Paris Descartes, Montrouge, France.,3 Centre de Référence des Maladies Rares du Métabolisme du Calcium et du Phosphore, Plateforme d'expertise Paris Sud Maladies rares, filière OSCAR, Hôpital Bicêtre-Paris Sud, AP-HP, Le Kremlin Bicêtre, France
| | - B R Coyac
- 4 EA 2496, Faculté de Chirurgie Dentaire, Université Paris Descartes, Montrouge, France
| | - C Bardet
- 4 EA 2496, Faculté de Chirurgie Dentaire, Université Paris Descartes, Montrouge, France
| | - C Zadikian
- 1 Service d'Odontologie, Hôpital Bretonneau, HUPNVS, AP-HP, Paris, France.,2 Faculté de Chirurgie Dentaire, Université Paris Descartes, Montrouge, France
| | - A Rothenbuhler
- 3 Centre de Référence des Maladies Rares du Métabolisme du Calcium et du Phosphore, Plateforme d'expertise Paris Sud Maladies rares, filière OSCAR, Hôpital Bicêtre-Paris Sud, AP-HP, Le Kremlin Bicêtre, France.,5 Service d'endocrinologie, Hôpital Bicêtre, HUPS, AP-HP, Le Kremlin Bicêtre, France
| | - P Kamenicky
- 3 Centre de Référence des Maladies Rares du Métabolisme du Calcium et du Phosphore, Plateforme d'expertise Paris Sud Maladies rares, filière OSCAR, Hôpital Bicêtre-Paris Sud, AP-HP, Le Kremlin Bicêtre, France.,5 Service d'endocrinologie, Hôpital Bicêtre, HUPS, AP-HP, Le Kremlin Bicêtre, France
| | - K Briot
- 3 Centre de Référence des Maladies Rares du Métabolisme du Calcium et du Phosphore, Plateforme d'expertise Paris Sud Maladies rares, filière OSCAR, Hôpital Bicêtre-Paris Sud, AP-HP, Le Kremlin Bicêtre, France.,6 Service de Rhumatologie, Hôpital Cochin, HUPC, AP-HP, Paris, France
| | - A Linglart
- 3 Centre de Référence des Maladies Rares du Métabolisme du Calcium et du Phosphore, Plateforme d'expertise Paris Sud Maladies rares, filière OSCAR, Hôpital Bicêtre-Paris Sud, AP-HP, Le Kremlin Bicêtre, France.,5 Service d'endocrinologie, Hôpital Bicêtre, HUPS, AP-HP, Le Kremlin Bicêtre, France
| | - C Chaussain
- 1 Service d'Odontologie, Hôpital Bretonneau, HUPNVS, AP-HP, Paris, France.,3 Centre de Référence des Maladies Rares du Métabolisme du Calcium et du Phosphore, Plateforme d'expertise Paris Sud Maladies rares, filière OSCAR, Hôpital Bicêtre-Paris Sud, AP-HP, Le Kremlin Bicêtre, France.,4 EA 2496, Faculté de Chirurgie Dentaire, Université Paris Descartes, Montrouge, France
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Koehne T, Jeschke A, Petermann F, Seitz S, Neven M, Peters S, Luther J, Schweizer M, Schinke T, Kahl-Nieke B, Amling M, David JP. Rsk2, the Kinase Mutated in Coffin-Lowry Syndrome, Controls Cementum Formation. J Dent Res 2016; 95:752-60. [PMID: 26927527 DOI: 10.1177/0022034516634329] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The ribosomal S6 kinase RSK2 is essential for osteoblast function, and inactivating mutations of RSK2 cause osteopenia in humans with Coffin-Lowry syndrome (CLS). Alveolar bone loss and premature tooth exfoliation are also consistently reported symptoms in CLS patients; however, the pathophysiologic mechanisms are unclear. Therefore, aiming to identify the functional relevance of Rsk2 for tooth development, we analyzed Rsk2-deficient mice. Here, we show that Rsk2 is a critical regulator of cementoblast function. Immunohistochemistry, histology, micro-computed tomography imaging, quantitative backscattered electron imaging, and in vitro assays revealed that Rsk2 is activated in cementoblasts and is necessary for proper acellular cementum formation. Cementum hypoplasia that is observed in Rsk2-deficient mice causes detachment and disorganization of the periodontal ligament and was associated with significant alveolar bone loss with age. Moreover, Rsk2-deficient mice display hypomineralization of cellular cementum with accumulation of nonmineralized cementoid. In agreement, treatment of the cementoblast cell line OCCM-30 with a Rsk inhibitor reduces formation of mineralization nodules and decreases the expression of cementum markers. Western blot analyses based on antibodies against Rsk1, Rsk2, and an activated form of the 2 kinases confirmed that Rsk2 is expressed and activated in differentiating OCCM-30 cells. To discriminate between periodontal bone loss and systemic bone loss, we additionally crossed Rsk2-deficient mice with transgenic mice overexpressing the osteoanabolic transcription factor Fra1. Fra1 overexpression clearly increases systemic bone volume in Rsk2-deficient mice but does not protect from alveolar bone loss. Our results indicate that cell autonomous cementum defects are causing early tooth loss in CLS patients. Moreover, we identify Rsk2 as a nonredundant regulator of cementum homeostasis, alveolar bone maintenance, and periodontal health, with all these features being independent of Rsk2 function in systemic bone formation.
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Affiliation(s)
- T Koehne
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany Department of Orthodontics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - A Jeschke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - F Petermann
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - S Seitz
- Department of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - M Neven
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - S Peters
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - J Luther
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - M Schweizer
- Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - T Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - B Kahl-Nieke
- Department of Orthodontics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - M Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - J-P David
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Abstract
Teeth are mineralized organs composed of three unique hard tissues, enamel, dentin, and cementum, and supported by the surrounding alveolar bone. Although odontogenesis differs from osteogenesis in several respects, tooth mineralization is susceptible to similar developmental failures as bone. Here we discuss conditions fitting under the umbrella of rickets, which traditionally referred to skeletal disease associated with vitamin D deficiency but has been more recently expanded to include newly identified factors involved in endocrine regulation of vitamin D, phosphate, and calcium, including phosphate-regulating endopeptidase homolog, X-linked, fibroblast growth factor 23, and dentin matrix protein 1. Systemic mineral metabolism intersects with local regulation of mineralization, and factors including tissue nonspecific alkaline phosphatase are necessary for proper mineralization, where rickets can result from loss of activity of tissue nonspecific alkaline phosphatase. Individuals suffering from rickets often bear the additional burden of a defective dentition, and transgenic mouse models have aided in understanding the nature and mechanisms involved in tooth defects, which may or may not parallel rachitic bone defects. This report reviews dental effects of the range of rachitic disorders, including discussion of etiologies of hereditary forms of rickets, a survey of resulting bone and tooth mineralization disorders, and a discussion of mechanisms, known and hypothesized, involved in the observed dental pathologies. Descriptions of human pathology are augmented by analysis of transgenic mouse models, and new interpretations are brought to bear on questions of how teeth are affected under conditions of rickets. In short, the rachitic tooth will be revealed.
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Affiliation(s)
- Brian L Foster
- National Institute for Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892
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22
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Linglart A, Biosse-Duplan M, Briot K, Chaussain C, Esterle L, Guillaume-Czitrom S, Kamenicky P, Nevoux J, Prié D, Rothenbuhler A, Wicart P, Harvengt P. Therapeutic management of hypophosphatemic rickets from infancy to adulthood. Endocr Connect 2014; 3:R13-30. [PMID: 24550322 PMCID: PMC3959730 DOI: 10.1530/ec-13-0103] [Citation(s) in RCA: 207] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In children, hypophosphatemic rickets (HR) is revealed by delayed walking, waddling gait, leg bowing, enlarged cartilages, bone pain, craniostenosis, spontaneous dental abscesses, and growth failure. If undiagnosed during childhood, patients with hypophosphatemia present with bone and/or joint pain, fractures, mineralization defects such as osteomalacia, entesopathy, severe dental anomalies, hearing loss, and fatigue. Healing rickets is the initial endpoint of treatment in children. Therapy aims at counteracting consequences of FGF23 excess, i.e. oral phosphorus supplementation with multiple daily intakes to compensate for renal phosphate wasting and active vitamin D analogs (alfacalcidol or calcitriol) to counter the 1,25-diOH-vitamin D deficiency. Corrective surgeries for residual leg bowing at the end of growth are occasionally performed. In absence of consensus regarding indications of the treatment in adults, it is generally accepted that medical treatment should be reinitiated (or maintained) in symptomatic patients to reduce pain, which may be due to bone microfractures and/or osteomalacia. In addition to the conventional treatment, optimal care of symptomatic patients requires pharmacological and non-pharmacological management of pain and joint stiffness, through appropriated rehabilitation. Much attention should be given to the dental and periodontal manifestations of HR. Besides vitamin D analogs and phosphate supplements that improve tooth mineralization, rigorous oral hygiene, active endodontic treatment of root abscesses and preventive protection of teeth surfaces are recommended. Current outcomes of this therapy are still not optimal, and therapies targeting the pathophysiology of the disease, i.e. FGF23 excess, are desirable. In this review, medical, dental, surgical, and contributions of various expertises to the treatment of HR are described, with an effort to highlight the importance of coordinated care.
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Affiliation(s)
- Agnès Linglart
- Service d'Endocrinologie et Diabétologie de l'EnfantHôpital Bicêtre, APHP78 rue du Général Leclerc , Le Kremlin Bicêtre, 94270France
- Université Paris 11 faculté de Médecine, Hôpital Bicêtre70 rue du général Leclerc, Le Kremlin-Bicêtre, 94270France
- Centre de Référence des Maladies Rares du Métabolisme du Calcium et du PhosphoreLe Kremlin-BicêtreFrance
- Correspondence should be addressed to A Linglart
| | - Martin Biosse-Duplan
- Centre de Référence des Maladies Rares du Métabolisme du Calcium et du PhosphoreLe Kremlin-BicêtreFrance
- Service d'Odontologie-Maladies Rares Hôpital Bretonneau 2 rue Carpeaux Paris, 75018France
- Université Paris Descartes 12 Rue de l'École de MédecineParis, 75006France
| | - Karine Briot
- Université Paris Descartes 12 Rue de l'École de MédecineParis, 75006France
- Service Rhumatologie B Hôpital Cochin, APHP27, rue du Faubourg Saint-Jacques, Paris, 75014France
| | - Catherine Chaussain
- Centre de Référence des Maladies Rares du Métabolisme du Calcium et du PhosphoreLe Kremlin-BicêtreFrance
- Service d'Odontologie-Maladies Rares Hôpital Bretonneau 2 rue Carpeaux Paris, 75018France
- Université Paris Descartes 12 Rue de l'École de MédecineParis, 75006France
| | - Laure Esterle
- Service d'Endocrinologie et Diabétologie de l'EnfantHôpital Bicêtre, APHP78 rue du Général Leclerc , Le Kremlin Bicêtre, 94270France
- Centre de Référence des Maladies Rares du Métabolisme du Calcium et du PhosphoreLe Kremlin-BicêtreFrance
| | - Séverine Guillaume-Czitrom
- Service de Pédiatrie générale – Consultation de rhumatologieHôpital Bicêtre, APHP78 rue du Général Leclerc , Le Kremlin Bicêtre, 94270France
- Centre de Référence des Maladies Rares des Maladies Auto-Inflammatoires Rares de l'EnfantLe Kremlin BicêtreFrance
| | - Peter Kamenicky
- Service d'Endocrinologie et des Maladies de la ReproductionHôpital Bicêtre, APHP78 rue du Général Leclerc , Le Kremlin Bicêtre, 94270France
- Université Paris 11 faculté de Médecine, Hôpital Bicêtre70 rue du général Leclerc, Le Kremlin-Bicêtre, 94270France
- Centre de Référence des Maladies Rares du Métabolisme du Calcium et du PhosphoreLe Kremlin-BicêtreFrance
| | - Jerome Nevoux
- Service d'ORL et chirurgie cervico-maxillo-facialeHôpital Bicêtre, APHP78 rue du Général Leclerc , Le Kremlin Bicêtre, 94270France
- Université Paris 11 faculté de Médecine, Hôpital Bicêtre70 rue du général Leclerc, Le Kremlin-Bicêtre, 94270France
| | - Dominique Prié
- Université Paris Descartes 12 Rue de l'École de MédecineParis, 75006France
- Service d'explorations fonctionnelles rénales, Hôpital Necker-Enfants Malades149 rue de Sèvres, Paris, 75015France
| | - Anya Rothenbuhler
- Service d'Endocrinologie et Diabétologie de l'EnfantHôpital Bicêtre, APHP78 rue du Général Leclerc , Le Kremlin Bicêtre, 94270France
- Centre de Référence des Maladies Rares du Métabolisme du Calcium et du PhosphoreLe Kremlin-BicêtreFrance
| | - Philippe Wicart
- Centre de Référence des Maladies Rares du Métabolisme du Calcium et du PhosphoreLe Kremlin-BicêtreFrance
- Université Paris Descartes 12 Rue de l'École de MédecineParis, 75006France
- Service de Chirurgie infantile orthopédiqueHôpital Necker-Enfants Malades149 rue de Sèvres, Paris, 75015 France
| | - Pol Harvengt
- Association de patients RVRH-XLH20 rue Merlin de Thionville, Suresnes , 92150France
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Lee JY, Imel EA. The changing face of hypophosphatemic disorders in the FGF-23 era. PEDIATRIC ENDOCRINOLOGY REVIEWS : PER 2013; 10 Suppl 2:367-379. [PMID: 23858620 PMCID: PMC4170520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In the past decade, research in genetic disorders of hypophosphatemia has significantly expanded our understanding of phosphate metabolism. X-linked hypophosphatemia (XLH) is the most common inherited form of rickets due to renal phosphate wasting. Recent understanding of the mechanisms of disease and role of fibroblast growth factor 23 (FGF-23) in XLH and other hypophosphatemic disorders have opened new potential therapeutic avenues. We will discuss the current standard of treatment for XLH as well as promising future directions under study.
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Affiliation(s)
- Janet Y Lee
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
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24
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Mineral and matrix changes in Brtl/+ teeth provide insights into mineralization mechanisms. BIOMED RESEARCH INTERNATIONAL 2013; 2013:295812. [PMID: 23802117 PMCID: PMC3681234 DOI: 10.1155/2013/295812] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 03/27/2013] [Accepted: 05/03/2013] [Indexed: 11/18/2022]
Abstract
The Brtl/+ mouse is a knock-in model for osteogenesis imperfecta type IV in which a Gly349Cys substitution was introduced into one COL1A1 allele. To gain insight into the changes in dentin structure and mineral composition in these transgenic mice, the objective of this study was to use microcomputed tomography (micro-CT), scanning electron microscopy (SEM), and Fourier transform infrared imaging (FTIRI) to analyze these structures at 2 and 6 months of age. Results, consistent with the dental phenotype in humans with type IV OI, showed decreased molar volume and reduced mineralized tissue volume in the teeth without changes in enamel properties. Increased acid phosphate content was noted at 2 and 6 months by FTIRI, and a trend towards altered collagen structure was noted at 2 but not 6 months in the Brtl/+ teeth. The increase in acid phosphate content suggests a delay in the mineralization process, most likely associated with the defect in the collagen structure. It appears that in the Brtl/+ teeth slow maturation of the mineralized structures allows correction of altered mineral content and acid phosphate distribution.
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25
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Abstract
The tooth root cementum is a thin, mineralized tissue covering the root dentin that is present primarily as acellular cementum on the cervical root and cellular cementum covering the apical root. While cementum shares many properties in common with bone and dentin, it is a unique mineralized tissue and acellular cementum is critical for attachment of the tooth to the surrounding periodontal ligament (PDL). Resources for methodologies for hard tissues often overlook cementum and approaches that may be of value for studying this tissue. To address this issue, this report offers detailed methodology, as well as comparisons of several histological and immunohistochemical stains available for imaging the cementum–PDL complex by light microscopy. Notably, the infrequently used Alcian blue stain with nuclear fast red counterstain provided utility in imaging cementum in mouse, porcine and human teeth. While no truly unique extracellular matrix markers have been identified to differentiate cementum from the other hard tissues, immunohistochemistry for detection of bone sialoprotein (BSP), osteopontin (OPN), and dentin matrix protein 1 (DMP1) is a reliable approach for studying both acellular and cellular cementum and providing insight into developmental biology of these tissues. Histological and immunohistochemical approaches provide insight on developmental biology of cementum.
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26
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Foster BL, Nagatomo KJ, Nociti FH, Fong H, Dunn D, Tran AB, Wang W, Narisawa S, Millán JL, Somerman MJ. Central role of pyrophosphate in acellular cementum formation. PLoS One 2012; 7:e38393. [PMID: 22675556 PMCID: PMC3366957 DOI: 10.1371/journal.pone.0038393] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 05/09/2012] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Inorganic pyrophosphate (PP(i)) is a physiologic inhibitor of hydroxyapatite mineral precipitation involved in regulating mineralized tissue development and pathologic calcification. Local levels of PP(i) are controlled by antagonistic functions of factors that decrease PP(i) and promote mineralization (tissue-nonspecific alkaline phosphatase, Alpl/TNAP), and those that increase local PP(i) and restrict mineralization (progressive ankylosis protein, ANK; ectonucleotide pyrophosphatase phosphodiesterase-1, NPP1). The cementum enveloping the tooth root is essential for tooth function by providing attachment to the surrounding bone via the nonmineralized periodontal ligament. At present, the developmental regulation of cementum remains poorly understood, hampering efforts for regeneration. To elucidate the role of PP(i) in cementum formation, we analyzed root development in knock-out ((-/-)) mice featuring PP(i) dysregulation. RESULTS Excess PP(i) in the Alpl(-/-) mouse inhibited cementum formation, causing root detachment consistent with premature tooth loss in the human condition hypophosphatasia, though cementoblast phenotype was unperturbed. Deficient PP(i) in both Ank and Enpp1(-/-) mice significantly increased cementum apposition and overall thickness more than 12-fold vs. controls, while dentin and cellular cementum were unaltered. Though PP(i) regulators are widely expressed, cementoblasts selectively expressed greater ANK and NPP1 along the root surface, and dramatically increased ANK or NPP1 in models of reduced PP(i) output, in compensatory fashion. In vitro mechanistic studies confirmed that under low PP(i) mineralizing conditions, cementoblasts increased Ank (5-fold) and Enpp1 (20-fold), while increasing PP(i) inhibited mineralization and associated increases in Ank and Enpp1 mRNA. CONCLUSIONS Results from these studies demonstrate a novel developmental regulation of acellular cementum, wherein cementoblasts tune cementogenesis by modulating local levels of PP(i), directing and regulating mineral apposition. These findings underscore developmental differences in acellular versus cellular cementum, and suggest new approaches for cementum regeneration.
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Affiliation(s)
- Brian L Foster
- Laboratory of Oral Connective Tissue Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
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27
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Sun JX, Horst OV, Bumgarner R, Lakely B, Somerman MJ, Zhang H. Laser capture microdissection enables cellular and molecular studies of tooth root development. Int J Oral Sci 2012; 4:7-13. [PMID: 22422086 PMCID: PMC3412663 DOI: 10.1038/ijos.2012.15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Epithelial-mesenchymal interactions (EMIs) are critical for tooth development. Molecular mechanisms mediating these interactions in root formation is not well understood. Laser capture microdissection (LCM) and subsequent microarray analyses enable large scale in situ molecular and cellular studies of root formation but to date have been hindered by technical challenges of gaining intact histological sections of non-decalcified mineralized teeth or jaws with well-preserved RNA. Here,we describe a new method to overcome this obstacle that permits LCM of dental epithelia,adjacent mesenchyme,odontoblasts and cementoblasts from mouse incisors and molars during root development. Using this method,we obtained RNA samples of high quality and successfully performed microarray analyses. Robust differences in gene expression,as well as genes not previously associated with root formation,were identified. Comparison of gene expression data from microarray with real-time reverse transcriptase polymerase chain reaction (RT-PCR) supported our findings. These genes include known markers of dental epithelia,mesenchyme,cementoblasts and odontoblasts,as well as novel genes such as those in the fibulin family. In conclusion,our new approach in tissue preparation enables LCM collection of intact cells with well-preserved RNA allowing subsequent gene expression analyses using microarray and RT-PCR to define key regulators of tooth root development.
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28
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Moriyama K, Hanai A, Mekada K, Yoshiki A, Ogiwara K, Kimura A, Takahashi T. Kbus/Idr, a mutant mouse strain with skeletal abnormalities and hypophosphatemia: identification as an allele of 'Hyp'. J Biomed Sci 2011; 18:60. [PMID: 21854633 PMCID: PMC3175157 DOI: 10.1186/1423-0127-18-60] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2011] [Accepted: 08/20/2011] [Indexed: 12/17/2022] Open
Abstract
Background The endopeptidase encoded by Phex (phosphate-regulating gene with homologies to endopeptidases linked to the X chromosome) is critical for regulation of bone matrix mineralization and phosphate homeostasis. PHEX has been identified from analyses of human X-linked hypophosphatemic rickets and Hyp mutant mouse models. We here demonstrated a newly established dwarfism-like Kbus/Idr mouse line to be a novel Hyp model. Methods Histopathological and X-ray examination with cross experiments were performed to characterize Kbus/Idr. RT-PCR-based and exon-directed PCR screening performed to identify the presence of genetic alteration. Biochemical assays were also performed to evaluate activity of alkaline phosphatase. Results Kbus/Idr, characterized by bone mineralization defects, was found to be inherited in an X chromosome-linked dominant manner. RT-PCR experiments showed that a novel mutation spanning exon 16 and 18 causing hypophosphatemic rickets. Alkaline phosphatase activity, as an osteoblast marker, demonstrated raised levels in the bone marrow of Kbus/Idr independent of the age. Conclusions Kbus mice should serve as a useful research tool exploring molecular mechanisms underlying aberrant Phex-associated pathophysiological phenomena.
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Affiliation(s)
- Kenji Moriyama
- Department of Medicine & Clinical Science, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya 663-8179, Japan.
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29
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Chen L, Liu H, Sun W, Bai X, Karaplis AC, Goltzman D, Miao D. Fibroblast growth factor 23 overexpression impacts negatively on dentin mineralization and dentinogenesis in mice. Clin Exp Pharmacol Physiol 2011; 38:395-402. [DOI: 10.1111/j.1440-1681.2011.05526.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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30
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Chu EY, Fong H, Blethen FA, Tompkins KA, Foster BL, Yeh KD, Nagatomo KJ, Matsa-Dunn D, Sitara D, Lanske B, Rutherford RB, Somerman MJ. Ablation of systemic phosphate-regulating gene fibroblast growth factor 23 (Fgf23) compromises the dentoalveolar complex. Anat Rec (Hoboken) 2010; 293:1214-26. [PMID: 20583265 DOI: 10.1002/ar.21152] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Fibroblast growth factor-23 (FGF23) is a hormone that modulates circulating phosphate (P(i)) levels by controlling P(i) reabsorption from the kidneys. When FGF23 levels are deficient, as in tumoral calcinosis patients, hyperphosphatemia ensues. We show here in a murine model that Fgf23 ablation disrupted morphology and protein expression within the dentoalveolar complex. Ectopic matrix formation in pulp chambers, odontoblast layer disruption, narrowing of periodontal ligament space, and alteration of cementum structure were observed in histological and electron microscopy sections. Because serum P(i) levels are dramatically elevated in Fgf23(-/-), we assayed for apoptosis and expression of members from the small integrin-binding ligand, N-linked glycoprotein (SIBLING) family, both of which are sensitive to elevated P(i) in vitro. Unlike X-linked hypophosphatemic (Hyp) and wild-type (WT) specimens, numerous apoptotic osteocytes and osteoblasts were detected in Fgf23(-/-) specimens. Further, in comparison to Hyp and WT samples, decreased bone sialoprotein and elevated dentin matrix protein-1 protein levels were observed in cementum of Fgf23(-/-) mice. Additional dentin-associated proteins, such as dentin sialoprotein and dentin phosphoprotein, exhibited altered localization in both Fgf23(-/-) and Hyp samples. Based on these results, we propose that FGF23 and (P(i)) homeostasis play a significant role in maintenance of the dentoalveolar complex.
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Affiliation(s)
- E Y Chu
- Department of Periodontics, School of Dentistry, University of Washington, Seattle, Washington, USA
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31
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Lee MM, Chu EY, El-Abbadi MM, Foster BL, Tompkins KA, Giachelli CM, Somerman MJ. Characterization of mandibular bone in a mouse model of chronic kidney disease. J Periodontol 2010; 81:300-9. [PMID: 20151810 PMCID: PMC2862731 DOI: 10.1902/jop.2009.090379] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Chronic kidney disease (CKD) is a worldwide health problem with increasing prevalence and poor outcomes, including severe cardiovascular disease and renal osteodystrophy. With advances in medical treatment, patients with CKD are living longer and require oral care. The aim of this study is to determine the effects of CKD and dietary phosphate on mandibular bone structure using a uremic mouse model. METHODS Uremia (U) was induced in female dilute brown agouti/2 mice by partial renal ablation. Uremic mice received a normal-phosphate (NP) or a high-phosphate (HP) diet. sham surgeries were performed in a control group of mice; half received an NP diet, and the other half was fed an HP diet. At termination, animals were sacrificed, and mandibles were collected for microcomputed tomography (micro-CT) and histologic analysis. RESULTS Sera levels of blood urea nitrogen, parathyroid hormone, and alkaline phosphatase were significantly increased in U/NP and U/HP mice versus sham controls, whereas serum calcium was increased in the U/HP group, and no differences were noted in serum phosphate levels among groups. Micro-CT analyses revealed a significant reduction in cortical bone thickness and an increase in trabecular thickness and trabecular bone volume/tissue volume in U/NP and U/HP groups compared to the sham/NP group. A significant reduction in cortical bone thickness was also found in the sham/HP group versus the sham/NP group. Histologic evaluation confirmed increased trabeculation in the U groups. CONCLUSION CKD in mice, especially under conditions of HP feeding, results in marked effects on alveolar bone homeostasis.
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Affiliation(s)
- Melissa M Lee
- Department of Periodontics, University of Washington School of Dentistry, Seattle, WA 98195-6365, USA
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